Commercial pressurestat for 110~120/220~240V equipment, #P302-6. This is the part that regulates your boiler heating via a diaphragm that expands and contracts as the boiler steam pressure raises and lowers, activating the contacts and sending a signal to the heating element telling it to turn on or off. It is by far the most commonly used pressurestat.
Of course in most cases any presurestat will work, but if there is room for it go with the Sirai. It is a purely mechanical part, and so there's no micro-switch to go out. The diaphrams go bad, and the contacts get fried. But the Sirai is essentially two or three pressurestats, depending on how many wires are used in your unit. There are six connections. When the contacts on the first set of contacts go bad, simply move the two wires over to the next available unused set.
Factory specification sheet here
Cross-references:
| Part number | Manufacturer |
| 20150 | ASTORIA CMA |
| 7433001 | BEZZERA |
| 5006010 | BFC |
| 00630.4.00.08 | BRASILIA |
| 000399 | BRUGNETTI-AURORA |
| 95.00275 | CARIMALI |
| 531-190-310 | CIMBALI |
| 00049035 | ELEKTRA |
| 558 | ESPRESSO RESOURCE |
| 60000000 | EXPOBAR |
| 60000005 | EXPOBAR |
| 2231116597 | FAEMA |
| 2231131900 | FAEMA |
| 531190310 | FAEMA |
| 5.2.000.0680 | FIEMMA RST |
| A2100050 | FIORENZATO C.S. |
| A2100314 | FIORENZATO C.S. |
| FC1669 | FRACINO |
| 07935703 | FUTURMAT-ARIETE |
| 12001274 | GAGGIA |
| WGADM0541 | GAGGIA |
| 07935703 | GAGGIA SPAGNA (SPAIN) |
| 1160800015 | GRIMAC |
| 1160800016 | GRIMAC |
| A2100314 | GRIMAC |
| GR814 | GRIMAC |
| GR815 | GRIMAC |
| GRC615 | GRIMAC |
| V070 | GRIMAC |
| 07935703 | ITALCREM |
| 10060660 | LAVAZZA |
| 10066203 | LAVAZZA |
| 07935703 | MAIRALI |
| L270 | MARZOCCO |
| 20150 | MCE |
| 09200006 | NUOVA SIMONELLI |
| D20150 | ORCHESTRALE |
| 451301 | PAVONI |
| 34200110 | RANCILIO |
| 34200111 | RANCILIO |
| 9005050 | RENEKA |
| GR814 | RICAMBI GARDOSI |
| GR815 | RICAMBI GARDOSI |
| GRC615 | RICAMBI GARDOSI |
| V070 | RICAMBI GARDOSI |
| 5006010 | ROYAL |
| SVTMP010 | SAB ITALIA |
| 1200127 | SAECO |
| WGADM0541 | SAECO |
| 108007 | SAN MARCO |
| 10602010 | SANREMO |
| 10602010A | SANREMO |
| C-0455 | SCALA |
| 01101 | SPAZIALE |
| 02623 | SPAZIALE |
| ELETPRE | VIBIEMME |
| 09200006 | VICTORIA ARDUINO |
| 07935703 | VISACREM |
| W10440 | WEGA |
| WY20150 | WEGA |